The starting address of the region to allocate. If the memory is being reserved, the specified address is rounded down to the nearest multiple of the allocation granularity. If the memory is already reserved and is being committed, the address is rounded down to the next page boundary.
To determine the size of a page and the allocation granularity on the host computer, use the GetSystemInfo function. If this parameter is NULL , the system determines where to allocate the region. If this address is within an enclave that you have not initialized by calling InitializeEnclave , VirtualAlloc allocates a page of zeros for the enclave at that address. The size of the region, in bytes. This means that a 2-byte range straddling a page boundary causes both pages to be included in the allocated region.
An attempt to commit a page that is already committed does not cause the function to fail. This means that you can commit pages without first determining the current commitment state of each page.
You can commit reserved pages in subsequent calls to the VirtualAlloc function. Other memory allocation functions, such as malloc and LocalAlloc , cannot use a reserved range of memory until it is released. If you want the range to contain zeros, decommit the memory and then recommit it.
A shared view is only acceptable if it is mapped to a paging file. This value cannot be used with any other value. The size and alignment must be a multiple of the large-page minimum. To obtain this value, use the GetLargePageMinimum function. To retrieve the addresses of the pages that have been written to since the region was allocated or the write-tracking state was reset, call the GetWriteWatch function.
The write-tracking feature remains enabled for the memory region until the region is freed. The memory protection for the region of pages to be allocated. If the pages are being committed, you can specify any one of the memory protection constants. If lpAddress specifies an address within an enclave, flProtect cannot be any of the following values:. Asked 11 years, 9 months ago. Active 2 years, 3 months ago. Viewed k times. Improve this question. There is no point in doing this.
On all modern OS the memory used by one application does not affect the memory available for other applications as it is all virtual. Only allocate what you require. LokiAstari: false of course. In linux and recent windows there is an OOM Killer that will chose an app to kill. Not to mention, if you have a page file, the system will trash and freeze to unusability.
Thus my comment stands. This useless virus would basically be painting a big red cross on it's chest, and on it's children's. Loki Astari Not everyone is here for the same reason, and it's pretry useful to write a garbage collector which collects more often when low on memory. Show 8 more comments. Active Oldest Votes. Improve this answer. Travis Gockel Travis Gockel This is useful for a tangentially related task I have: to warn the user when they're using a significant fraction of physical memory.
I know I can use more and have virtual memory managed, but if I am using more than the amount of physical RAM I want to be able to warn the user, because this will result in a slow-down because of the resulting paging that will occur. Minor nitpick: status. Running the code as-is results in a return value of on my system, but changing it to match the type of ullTotalPhys results in the correct That's a good point Show 9 more comments.
Paresh M Paresh M 3 3 silver badges 2 2 bronze badges. It was not exactly scientific software, rater I was than building an ETL framework, off course it was intended to run on dedicated servers. Probably, it needed to ave a maximum allowed memory like, Java or Maltab takes as start-up parameter. There are reasons to do this with rendering software at least. You want to use as much memory as you have. Add a comment. Community Bot 1 1 1 silver badge.
Weather Vane Weather Vane A fun approach could also try to allocate and write to 1 until failure to detect the memory available. This is an extremely horrible solution. Imagine that you are working on a computer, and suddenly it starts swapping and slows down to a crawl, and some applications fail due to insufficient memory, and a network connection fails, etc.
You panic that you have malware, shutdown or run antivirus, and find out that this was cause by some dumb application just constantly allocating and freeing humongous amounts of memory that it doesn't even need.
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Privacy policy. The following is a list of the reference content for the Windows application programming interface API for desktop and server applications. Using the Windows API, you can develop applications that run successfully on all versions of Windows while taking advantage of the features and capabilities unique to each version.
Note that this was formerly called the Win32 API. The Windows UI API create and use windows to display output, prompt for user input, and carry out the other tasks that support interaction with the user.
Most applications create at least one window. Globalization Services. Windows Animation Manager. Windows Ribbon Framework. Legacy User Interaction.
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